The present invention generally relates to tissue punches, such as aortic punches used during heart surgery, and more specifically relates to a tissue punch which is configured to use a spring force to compress tissue and then a rotation movement to effect a cut of the tissue.
Another aspect of the present invention generally relates to methods for creating an anastomosis for locating a bypass graft, and more specifically relates to methods which provide that bypass graft material is installed on a tissue punch and then sutured. Depending on the specific method performed, the tissue is cut either before or after the suturing.
Often the goal of heart surgery is to produce blood flow paths around the diseased areas of coronary arteries. To provide as such, saphenous vein grafts are used wherein an opening is formed in the wall of an ascending aorta, then a proximal end of a saphenous vein is anastomosed thereto. To form the opening in the wall of the aorta, an incision can be made using surgical scalpels and/or scissors. Then, an aortic punch can be used in order to attempt to obtain a clean, accurate somewhat larger opening in the aortic wall. Obtaining a clean and accurate opening is extremely important since an opening which is not formed cleanly and accurately often is frayed (albeit microscopically). As a result, the connection of the proximal end of the saphenous vein thereto may not be as reliable, and complications during or after surgery may result. Additionally, rough cut holes as the bypass ostium serve as points for calcification or occlusions. Because heart surgery necessarily often entails the difference between life and death of the patient, it is extremely important to maximize the probability of success of every aspect of the surgical procedure. To this end, it is desirable to try to obtain as clean and as accurate an opening as possible in the wall of the aorta before grafting the saphenous vein thereto.
As mentioned, in attempting to obtain as accurate an opening as possible in the wall of the aorta, surgeons often utilize an aortic punch to form the opening. Typically, the aortic punch will include an anvil, or other support, which is first inserted into the aorta through a small incision in the wall. Then, the surgeon takes his or her hand and approximates the thumb and opposed first and second fingers to push a thumb button while pulling a cross-bar. Consequently, a cutting tube of the aortic punch extends, and slides past, the anvil, thus shearing a larger opening in the aortic wall. Finally, the anvil and cutting tube of the aortic punch are withdrawn from the incision in the wall of the aorta. Examples of prior art aortic punches and similar devices can be found in the following U.S. Pat. Nos. 1,867,624; 3,701,352; 4,018,228; 4,216,776; 5,129,913; 5,192,294; 5,403,338; 5,690,662; 5,827,316 and U.S. Design Pat. No. D372,310.
Because the aortic punch accomplishes cutting the opening in the wall of the aorta by shearing, and effects this shearing by sliding the cutting tube past the anvil, the cut produced is not always extremely clean and accurate, and some fraying of the aortic wall may result. The quality of cut and occurrence of pinching depends upon the fineness and toughness of tissue encountered as well as the sharpness of punch cutting edges and closeness of running clearances among shearing surfaces. A typical aortic punch can often pinch very thin, tough tissue within the close-running, moving punch components, leading to an incomplete hole cutting operation and jamming of the mechanism. Moreover, because the aortic wall is extremely durable, the surgeon must typically exert considerable hand pressure to successfully manipulate the aortic punch to shear the aortic wall. Because shearing of the aortic wall is performed merely by axially sliding a cutting tube across an anvil, the cutting tube of the aortic punch does not remain sharp for very long. Therefore, the cutting tube must be sharpened often, or must be replaced frequently with a sharper cutting tube. Finally, a typical aortic punch is not configured to provide the surgeon with total tactile control of the cutting process, such as effecting a cut only during the pressing of a button or plunger, but not during release of the button or plunger. It is advantageous to provide that the surgeon has effectively total tactile control over the cutting process.
For at least the foregoing reasons, there is a need for an improved tissue punch which can be used to obtain a very clean and accurate opening in tissue without any fraying, which can be used without having to exercise any excessive hand pressure, which does not jam during operation, which does not require that a cutting tube be sharpened or replaced very frequently and which effectively provides the surgeon with total control of the tissue cutting process.